If you are deemed non-resident for tax purposes by the Canada Revenue Agency today, they will tell you that's 'today'. Tomorrow is another matter as tax law changes. So might your tax status, so be careful. They will also tell you having a letter stating that you are non-resident for tax purposes doesn't go much beyond the day it was written or issued.
Your tax status will most probably be assessed upon your return.
Like the gentleman said, cut all your ties with Canada. The safest bet here.
(I'd stay away from Cdn banks for off-shore banking btw, as Ottawa has tight control and cnx via the BOC to check records) If you're with RBC in DXB you might want to reconsider things.
The gen decs you complete when you scoot in and out of the country also tell them how many days you've been in-country so, be careful of the 180 rule.
There is a story circulating about a Cdn Dr. who worked in the Gulf for 15 years. Shortly after his re-patriation to Canada, the CRA did their assessment and apparently, the Dr's wife had maintained her B.C. driver's licence and a Sears card for the entire time they were out of the country.
Since you can't maintain a Cdn Driver's licence without a Cdn residential address, they were deemed residents of Canada for tax purposes and he was assessed 15 years back taxes. (ouch!!)
You see, we're taxed on worldwide income. Even if it hurts.
Be careful out there and don't take my advise. Seek a professional Canadian financial advisor working the ME and Gulf circuit who's versed in Cdn tax law.
If you think Canada has friendly tax laws for expats, you're dreaming in colour.